Electronic Components Datasheet Search |
|
HSP50215 Datasheet(PDF) 10 Page - Intersil Corporation |
|
HSP50215 Datasheet(HTML) 10 Page - Intersil Corporation |
10 / 21 page 3-431 Carrier NCO The Carrier NCO provides the quadrature local oscillator references for the Vector Modulator/Mixer. The Carrier NCO input carrier frequency control word has 32 bits of resolution. The block diagram is shown in Figure 10. The carrier frequency is a single buffered 32-bit frequency control, loaded 16 bits at a time into Control Words 4 and 5. Since the DUC requires two loads, there is a possibility of a phase glitch. The Carrier NCO is disabled during a RST assertion or a reset caused by writing to CW21. The Carrier NCO stays disabled until a sync assertion is detected independent of the initiating sync source (SYNCIN or WR CW3). The Carrier NCO is also disabled by programming a zero in Control Word 16 bit 3. This bit freezes the NCO and also disables the output of the modulator. To avoid the phase glitch, noted above, the phase accumulator can be disabled at reset, and the frequency can be pre-loaded prior to asserting sync. The maximum error is 52MHz/(232) = 0.012Hz for the commercial part and 0.011Hz for the industrial part. The carrier frequency can be calculated from the value loaded into Control Address 4 and 5 by: where CR(31:0) is the 32-bit frequency control word which can range from -231 to ~231 for a NCO output range of -fCLK/2 to ~fCLK/2. fCLK is the REFCLK frequency. This NCO frequency range allows for spectral inversion. Given a desired carrier frequency, the value for CR(31:0) loaded into the part can be calculated by: where INT[X] is the integer part of the real number X. The most significant 18 bits of the 32-bit phase word from the Carrier NCO drives a Sin/Cos generator. Eighteen bit resolution is supplied on the sinusoid outputs. Assertion of RST stops the Carrier NCO and clears the accumulator contents. It is held disabled until a SYNCIN or write to Control Word 3 generates an EnNCO signal to restart the NCO. Vector Modulator/Mixer The frequency resolution of the vector modulator is 32 bits. The conceptual block diagram of the Vector Modulator/Mixer is shown in Figure 11. The modulator operates at maximum frequency of 52MHz (commercial). The mixer takes the sin/cos terms generated by the carrier NCO sin/cos generator and mixes it with the input data lines I and Q. The resulting output is given by NOTE: There is no overflow protection provided at the output of the modulator summer, so care must be taken to ensure that the input signals are scaled prior to input to prevent overflow. The mixers can be bypassed by programming Control Words 4 and 5 to zero, which sets COS = 1 and SIN = 0. FIGURE 10. CARRIER NCO BLOCK DIAGRAM 32 SYNCIN WR CW3 CARRIER SIN/COS SYNCSEL † ALL REGISTERS ARE CLOCKED AT REFLCK GEN EN OUT FREQUENCY 18 18 TO MODULATOR OUTPUT SIN COS WR CW21 RST RESET GEN EDGE START GEN EDGE ∑ R E G > R E G > R E G > R E G > R E G > EnNCO ACC REG > 32 F CARRIER CR 31:0 () f CLK 2 32 – × × = (EQ. 7) CR 31:0 () INT F C fCLK ⁄ *2 32 ] [ = (EQ. 8) Output I * cos Q * sin – = (EQ. 9) FIGURE 11. VECTOR MODULATOR/MIXER BLOCK DIAGRAM 16 I(15:0) SIN 16 Q(15:0) COS 16 EN OUT MOD(15:0) 18 18 ∑ + - HSP50215 |
Similar Part No. - HSP50215 |
|
Similar Description - HSP50215 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |